Bolt or nut running machines or stopers



Nov. 4,' 1958 J. A. LARCEN Filed Oct- 11; 1955 BOLT OR NUT RUNNING MACHINES OR STOPERS 2 Sheets-Sheet 1 IIH 2 ig/ .z I

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" ATTORNEY i United States Patent 2 ,858,722 i p BOLTOR NUT RUNNING MACHINES 0R STOPERS Jan August Larcn, Ekto'rp, Sweden, assignor to Atlas gopgo Aktiebolag, Nacka, Swedenpa corporation of we en e Application October 171, 1955, Serial No. 539,861

4 Claims. or 81-524 This invention relates to improvements in bolt or nut running machines or stopers having a rotary bolt or nut engaging chuck or socket and operable to produce rotary blows, i. e. a rotational hammering action or intermittent torque. One object of the invention is to enable tightening of bolts or nuts with such machines with a carefully predetermined torque. Upon tightening of nuts or bolts with ordinary impact wrenches or with machines according to U. S. application Ser. No. 500,579, filed April 11, 1955, by Sven Erik Ryd, it is diflicnlt to know exactly to what extent the bolt or nut has been tightened and it often occurs that it is tightened too much or too little. In the latter case it is of course possible to continue the tightening by hand with a so-called safety wrench but this is diflicult and time-wasting and in the former case it is impossible to know to what extent the bolt has been stressed by the tightening and it may consequently readily happen that the bolt is broken by such continued tighten ing. If the bolt happens to be a rock anchor bolt, severe accidents and great damage may result from the breakage of a bolt. In order to obtain a bolt or nut running machine or stoper which avoids the above mentioned disadvantages 1 provide a machine of the type described having a casing, a power rotated chuck or socket, an arm extending transversely to the rotary axis of said chuck or socket from said casing, handles for holding said casing against rotation to take up the torque reaction from said power rotated chuck or socket, one of said handles being provided at the free end of said arm, and means between said handles and the casing yielding to a predetermined torque reaction.

In the accompanying drawings one embodiment of a bolt or nut running stoper according to the invention is illustrated by way of example. Fig. 1 is a side elevation partially broken of a combined rock drill and nut running stoper according to the invention. Figs. 2 and 3 show some details on a larger scale partially in section. Fig. 2 is substantially a section on line II-II in Fig. 1 and Fig. 3 is a side view and section on line III-III in Fig. 2.

The nut running stoper illustrated in Fig. 1 is of the same design as the stoper illustrated in the aforesaid application Serial No. 500,579, but the invention may be employed in connection with other types of impact wrenches, for instance impact wrenches of the type illustrated in our Swedish Patent No. 126,061, or the like.

The combined rock drill and nut running stoper illustrated in the drawings consists of a casing 1 containing a mechanism known per se for delivering rotary impact or blows through a power rotated nut socket or chuck 2 which is journalled for rotation in the machine. Reference character 3 designates a handle of a valve for controlling the supply of compressed air to the machine from a compressed air source which is connected through a hose 4. Reference character 5 designates a conventional telescopically expansible supporting mechanism, for instance of the type illustrated in U. S. Patent No. 2,689,547, to Pearson, and reference character 6 designates an adjustable valve device for controlling the supply 2. of compressed air to and the air pressure in the supporting mechanism. The valve device 6 forms part of a handle 22 provided on an arm 23 extending transversely from thelcasing 1. i

According to the invention the'mac'hine is provided with a second arm 7 extending from the casing 1 transversely to the axis of rotation of the chuck or socket 2 and having a handle 8Yformed at the free end thereof. The arm is divided into sections pivotally connected by means of a pivot 9 'so that the outer section 10 may be bent relative to the innersection" 7 which is rigidly secured to the machine ,1 by means of a tapering sleeve 11 locked by a nut 12 and screwed on to a threaded portion 24 at the inner end on the arm 23. A sleeve 13 is slidable in the longitudinal direction of the arm 7, 10 from a position illustrated in chain dotted lines in Figs. 2-3 and indicated at 14 and in which position the sleeve does not prevent bending of the arm to a position illustrated in full lines and indicated at 29 in which the sleeve locks the sections 10 and 7 against bending. vIn the arm section 10 a ball 15 is movable against the action of a spring 16 the tension of which may be adjusted by means of a screw threaded plug 17 having an internal hexagon opening. The tension of the spring 16 may be changed by screwing the plug 17 more or less into the end of the arm section 10 by means of a suitable wrench. The spring 16 is fitted between a rod 24 having a head 25 forming a shoulder and a bushing 26 slidable in the arm section 10. A roller 18 of cylindrical shape is loosely fitted in the arm section 7 and forms a cam which cooperates with the ball 15 and tends to force the ball 15 away against the action of the spring 16. The roller 18 is held in position axially by the inner side walls 27 of a forked portion 28 of the arm section 10. If the arm 10 in Fig. 2 is pressed downwardly after the sleeve 13 has been moved to the position 14 then it is obvious that the tension of the spring 16 determines the torque at which the arm joint bends or yields and consequently the torque with which the nut may be tightened by means of the arm 7, 10. If this torque, which is the torque reaction of the torque with which the bolt or nut is drawn, is exceeded the ball 15 compresses the spring 16 and moves into a recess 19. When the arm 7, 10 yields the operator stops the machine. Spring actuated balls 20 in the arm section 10 cooperate with recesses 21 in the sleeve 13 to keep the sleeve in the position 29 or 14, respectively.

The rock drilling and nut running stoper according to the invention described hereinabove should be considered only as an example and the details of the invention may be modified in several different ways within the scope of the claims.

What I claim is:

1. A bolt or nut running machine having a power rotated bolt or nut engaging chuck or socket and having a casing, an arm extending transversely to the rotary axis of said chuck or socket from said casing and secured to the casing at one end, handles for holding said casing against rotation to take up the torque reaction from said power rotated chuck or socket, one of said handles being provided at the free end of said arm, and means in said arm between said handle and the casing yielding to a predetermined torque reaction.

2. A stoper rock drill having a power rotated bolt or nut engaging chuck or socket and having a casing, two arms fixed to said casing and extending transversely to the rotary axis of said chuck or socket from said casing, handles at the free ends of said arms and means between said handles and casing yielding to a predetermined torque reaction from the rotation of the chuck or socket.

3. A stoper rock drill having a casing, a power rotated bolt or nut engaging chuck or socket at one end of said casing, and a telescopic supporting mechanism at the opposite end of the casing, two arms extending transversely to the rotary axis of said chuck or socket from said casing, handles at the free ends of said arms, means between one of said handles and. the casing yielding to a predetermined torque reaction from the rotation of the chuck or socket and means for controlling the operation of said supporting mechanism at said other. handle.

4. A stoper rock drill having .a casing, a power rotated bolt or nut engaging chuck or socket at one end of said casing, and an expansible supporting leg at the opposite end of the casing, an arm extending'transversely .to the rotary axis of said chuck orsocket-from said casing and comprising two sections connected with each other-by a pivotal joint, means for preventing pivotal movement at said joint until a predetermined torque reaction is applied,

4 and an adjusting mechanism for said means for setting the same at a desired torque vvalue.

References Cited in the file of this patent UNITED STATES PATENTS 1,099,079 Alden June 2, 1914 1,298,504 Hollingsheadllj; Mar. 25, 1919 1,743,241 .Schr'nidt Jan. 14, 1930 2,362,149 Nelson -Q. Nov. 7, 1944 2,680,596 Houston June 8, 1954 2,689,547 Pearson Sept. 21, 1954 2,731,865 Woods L Jan. 24; 1956 FOREIGN PATENTS 300,377 Germany May 12, 1915 407,362 Italy l. Oct. 3, 1944 

